1. Field of the Invention
This invention relates to a polysilazane perhydride solution and a method for manufacturing a semiconductor device by using a polysilazane perhydride solution.
2. Description of the Related Art
An isolation structure known as an STI (Shallow Trench Isolation) structure is extensively employed for the isolation of elements in a semiconductor device. This STI structure can be created by a method wherein a trench is formed in an element isolation region of a semiconductor substrate, and then, a silicon oxide (SiO2) film functioning as an element isolating insulation film is buried inside this trench to form this STI structure. Recently however, due to the increase in aspect ratio of the trench for meeting demands for enhancing the fineness of semiconductor elements, it is now becoming increasingly difficult to bury the conventional ozone (O3)-TEOS CVD-SiO2 film or HDP CVD-SiO2 film in the trench of STI structure without causing the generation of voids or a seam.
Therefore, in the manufacture of a semiconductor device where the fineness of semiconductor elements is in the order of 100 nm or less, it has been proposed to fill the STI trench with an element isolating insulation film by using a coating type solution SOG (Spin-On-Glass). As for the SOG solution, a chemical comprising silicon hydroxide (silanol: SiOH4) dissolved in an organic solvent such as alcohol is generally employed. This silicon hydroxide solution is coated on a substrate to form a coated film, which is then heat-treated. Due to this heat treatment, the hydrolysis and dehydrocondensation reaction of silanol generate, thereby converting the coated film of silicon hydroxide solution into a silicon dioxide film. On the occasion of the hydrolysis and dehydrocondensation reaction of silanol however, a large magnitude of volumetric shrinkage generated in the coated film, resulting in the generation of cracks in the silicon dioxide film filled in the STI trench.
Under the circumstances, a polysilazane perhydride solution which is relatively low in volumetric shrinkage is noticed as useful for the SOG type chemical in recent years.